Both these salmon are the same age, but the one behind is genetically modified. AquaBounty Technologies plans to hatch eggs for genetically modified salmon at a plant in Bay Fortune, P.E.I., and then ship the eggs to Panama for rearing. (AquaBounty)

A review of the environmental impact of genetically-modified salmon by the U.S. Food and Drug Administration is too narrow, say researchers at Duke University.

AquaBounty Technologies plans to hatch eggs for the salmon at a plant in Bay Fortune, P.E.I., and then ship the eggs to Panama for rearing. The fish are genetically modified to grow at twice the speed of regular salmon.

The FDA released a statement earlier this year saying AquaBounty's product is as safe to eat as other Atlantic salmon. If the fish are approved for sale, it would be the first genetically modified food animal to be consumed in the world.

The Duke researchers say the FDA hasn't looked at all the potential impacts, including how the new development could affect the market for salmon.

"As with many technologies, when you build a better mouse trap, so to speak, you might lower the cost of production. Given the way the market works, that might lower price, and more consumers will have access to it," Martin Smith, a professor of environmental economics at Duke, told CBC News Wednesday.

"But no one has been able to figure out how to farm salmon without feeding it wild fish. And those stocks of fish might not be managed well. So if you increase the demand for that fish meal and that fish oil you can exacerbate problems with overfishing in some places."

Smith's concerns were published in a paper in the magazine Science last week.

Smith said looking at the broader environmental impact might not change the decision in this case, but the precedent of doing a broader study is important.

The FDA could release its ruling on the salmon at any time.